As public safety users increasingly use broadband devices, many users carry multiple communication devices. For example, broadband devices provide new portable data services, such as, public safety database query, video, and image sharing, as well as a supplementary push-to-talk (PTT) service. It is anticipated that the PTT service on the broadband device will be used as a backup to the primary PTT service on a narrowband device, for example, allowing the user to continue monitoring conversations even when there is a gap in narrowband coverage. It is likely in this use case that the broadband device will be provisioned with and affiliated with the same talkgroups as the narrowband device.
PTT communication services generally use a loudspeaker to play the audio received from a communication source in either point-to-point/private communications or group communications. Without special consideration, each communication device in the communication is treated individually. Thus, audio that is being transmitted by a user on one of the communication devices is played out of the loudspeaker on the user's other communication device(s).
While convenient, the audio being played back or rendered at the receiving communication device could be picked up by the open microphone of the transmitter, thus resulting in a feedback loop which could potentially cause the communication, for example, audio quality, to become unusable. In addition, when the source of the communication is transmitting on a narrowband device and the communication is being played back or rendered at a broadband device, the audio being played back will typically be delayed relative to the talker. It is often distracting for a talker to hear herself/himself talk with a delay. Further, the talker will typically start listening to herself/himself rather than focusing on what s/he is saying. In other words, the delay of playback on the broadband device is likely to be noticeable and could exacerbate this effect.
One solution is for a talker to manually turn down the volume of the loudspeaker on the broadband device so as not to hear herself/himself talk. Users, however, often forget to turn the volume back up after they finish talking, which can result in missed communications. Another example of this problem today is when officers carry a portable narrowband device, such as a portable radio, and turn its volume down when they enter a vehicle that also has a mobile radio affiliated to the same talkgroup as the portable device. The officer may forget to turn the volume back up on the portable narrowband device when leaving the vehicle.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments. In addition, the description, drawings and claims do not necessarily require the order illustrated unless explicitly stated.
It will be further appreciated that certain actions and/or steps may be described or depicted in a particular order of occurrence while those skilled in the art will understand that such specificity with respect to sequence is not actually required.
Apparatus and method components have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the various embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Thus, it will be appreciated that for simplicity and clarity of illustration, common and well-understood elements that are useful or necessary in a commercially feasible embodiment may not be depicted in order to facilitate a less obstructed view of these various embodiments.